Bhikkhuni Vajjira was a bhikkhuni during the time of the Buddha.
Nagasena asks if the pole of the chariot is the chariot. Answer, no. Nagasena asks if the axel is the chariot or if the wheels are the chariot. Answer, no. Nagasena asks if the reins are the chariot. To this and further questions about the parts, the answer is no. Nagasena explains that the chariot is not something other than these parts. Yet the parts are not the chariot. Nagasena states that chariot is just a word, it exists, but only in relation to the parts. The concept "chariot" does not have an intrinsic, inherent value or place as something permanent. It is the same with the self. We certainly exist, just as a chariot exists, but it is more in terms of conventional language as opposed to absolute language.
Nagasena developed this excellent teaching from the wise words of Venerable Vajjira. She once remarked:
"Just as, with an assemblage of parts, the word chariot is used, so when the aggregates exist, there is the convention of being." Samyutta Nikaya 5.554